The subject matter disclosed herein relates to X-ray imaging systems and more particularly to X-ray imaging systems using digital detectors.
A number of radiological imaging systems of various designs are known and are presently in use. Such systems generally are based upon generation of X-rays that are directed toward a subject of interest. The X-rays traverse the subject and impact a film or a digital detector. Increasingly, such X-ray systems use digital circuitry for detecting the X-rays, which are attenuated, scattered or absorbed by the intervening structures of the subject. In medical diagnostic contexts, for example, such systems may be used to visualize internal tissues and diagnose patient ailments. In other contexts, parts, baggage, parcels, and other subjects may be imaged to assess their contents and for other purposes.
Basic X-ray systems may be designed for generating projection images only. Such projection images may be presented as a well-known reverse image, although the image data itself is subject to various presentations. In addition to projection X-ray systems, the art now offers fluoroscopy systems, computed tomography systems, and tomosynthesis systems that are based on similar X-ray radiation generation and detection. In computed tomography and tomosynthesis systems, for example, images are computed as slices through the subject based upon various reconstruction techniques applied to multiple collected images.
Various artifacts may be present in radiological system data collected in any one of the foregoing types of systems. Certain types of artifacts are well-known and can be handled, eliminated or corrected in various known ways. However, there are still artifacts that cannot be easily corrected or avoided, at least by known techniques. For example, X-ray systems with digital detectors suffer from artifacts due to the presence of electronic noise, particularly in applications where the X-ray dosage is low. In particular, an offset corrected image generated from image data and offset data may include even greater amounts of electronic noise compared to the original image. The problem is further exacerbated when the offset corrected image is generated from multiple imaging frames that include X-ray data increasing the electronic noise. Such electronic noise may adversely impact the quality of the image and, thus, the effective use of the image.
There is a need, therefore, for improved approaches to the elimination of electronic noise in radiological image data. There is a particular need for a technique that can address electronic noise in X-ray images.